Every so often a story turns up in the news about a cat that managed to find its way home, or to an old home, from a long distance away, occasionally hundreds of miles. On a more mundane level, many cat owners have experienced the problem of moving to a new house a short distance from home, only to get a phone call from the new owners of the old house, saying their cat has turned up there. So how do cats do this?

What is Homing Ability?

'Homing' is the ability of some animals and birds to find their way home from an unknown and unfamiliar location. This may be either a home territory or a breeding spot. It is an ability which is well documented in pigeons and some other animals. Homing can be used by some species to find the way back to home in a migration. It is often used in reference to going back to a breeding spot seen years before, as in the case of salmon. Homing abilities can also be used to go back to familiar territory when displaced over long distances, such as with the red-bellied newt.

Examples of Cats' Homing Ability

There are numerous recorded cases of cats travelling a few miles to get to an old home. A cat called Tigger made the three-mile round trip to his old home an amazing 75 times, no mean feat considering he only had three legs. Then there was Pilsbury, who went back home after his owners moved eight miles away, and did it 40 times.

A few cats have travelled far greater distances. For example, the story of Sushi made headlines in the animal world in September of 2013, when she turned up two years after getting lost during her family’s evacuation from out-of-control wild­ fires near Austin, Texas. No one knows where she had been all that time, but wherever it was, she brought a feral black kitten home with her. Ninja moved with his family from Farmington, Utah to Mill Creek, Washington – a huge distance. He left the new house and showed up in Utah one year later, after travelling a distance of 850 miles.

And perhaps the most incredible story is that of Howie, a Persian cat, crossing the Australian outback and travelling over 1,000 miles, to return to his home.

How is Homing Possible?

Scientists have discovered that migratory birds like geese use visual cues such as rocks and landscapes, as well as the orientation of the sun, moon and stars, to ­find their way. Salmon use scent cues to return to their home waters thousands of miles away. Still other animals use magnetic cells in their brains to orient them to true north.

Exactly how cats do this, however, remains a mystery. Part of the problem is that cats do not move in large numbers, in the way that migrating birds do, for instance. So it is quite difficult to study them. And doing experiments on homing ability in cats is probably rather unethical, though a few have been done.

Experiments on Cats' Homing Ability

In a fairly wellknown experiment, which is now nearly 100 years old, Herrick (1922) tested the homing powers of a single cat by transporting her to seven different locations between one and three miles from her home. He ensured that she was highly motivated to return home because she had a litter of kittens close to weaning age. At each location, the cat was transported by car in a gunny sack and then placed under a wooden box. The researchers opened the box remotely and then observed the cat’s behaviour until she was out of sight. Then they waited for her to return home to her kittens. In a final trial they took her 16.5 miles away, and she did not return home. I was not able to find out what happened to her poor kittens!

Leaving aside the ethics of this experiment, the results are quite interesting. In every case, the cat seemed to know the correct direction of home as soon as she was released. In a later experiment in 1954, the researchers found the same thing in relation to direction, but at distances greater than about three miles this did not work so well. Anecdotal evidence suggests that some cats are much better at homing than this, which suggests that some cats are more successful at it than others. This is probably to be expected in a species which shows such a great amount of individual variation in so many other ways.

Theories About Cats' Homing Ability

Despite the lack of hard evidence, there are a number of theories about homing in cats.

Some researchers think that homing may be due to an unusual sensitivity to the geo-magnetic field of the earth, which enables the cat to keep a compass fix on their home region, regardless of distance and direction travelled. Perhaps not all cats have this same level of sensitivity, which might account for the differences in their homing ability.

One animal behaviourist postulated that homing ability in cats is genetic, and suggested that all cats possess some degree of homing instinct, but some may be genetically predisposed to having a better sense of direction than others. She suggested that whether or not cats use this skill is likely influenced by experience - a feral cat will exercise the skill on a regular basis, whereas an indoor cat that gets lost outside might not be able to do so. Motivation also probably influences a cat’s will to return ‘home’, she suggested – the presence of young, reliable shelter, food, and so on.

Another researcher offers a mix of theories. “Cats likely rely on their somatosensory system,” he says. “They may possess some unidentified geo-magnetic polarity cellular structure, or perhaps it’s a mix of olfactory cues and magnetic fields. He continues: “Another hypothesis that may be at play involves the disequilibrium that forms when closely-bonded individuals get separated. This phenomenon is illustrated by Bell’s Theorem, which proposes that ‘all electrons function in pairs, with each electron spinning in the opposite direction of the other electron’. When the spin of one electron is changed, the other senses it and alters its direction according to the ­first one. In space experiments, when the spin of one electron was changed, its bonded electron back on earth correspondingly and immediately altered its own spin. Perhaps when the physical bond between a cat and his family is disrupted by separation, this disequilibrium helps to drive them back to homeostasis.”

Conclusion

These theories are intriguing, but they don't really explain how cats manage to find their way home over great distances, or why humans and other species don't possess such good homing ability. Clearly this ability will remain a mystery for some time to come, along with so many other aspects of that beautiful but mysterious animal, our domestic cat.